title: Does single-dose cell resistance to the radio-mimetic zeocin correlate with a zeocin-induced adaptive response in Chlamydomonas reinhardtii strains?
abstract: This study aimed to test whether a correlation exists between single-dose resistance to zeocin and the ability to develop a zeocin-induced adaptive response (AR) in Chlamydomonas reinhardtii strains. Three genotypes were used: wild type (WT) strain 137C and two strains (H-3 and AK-9-9), which are highly resistant to radiation based on survival studies. Based on a micro-colony assay, the strains could be arranged according to their single-dose resistance to zeocin as follows: AK-9-9 > H-3 > 137C. However, zeocin induced a similar level of DSB in strains AK-9-9, H-3 and 137C. The radio- and zeocin-resistant strains AK-9-9 and H-3 showed higher DSB rejoining capacity than the WT strain 137C, suggesting that DSB rejoining can at least partly account for different cell survival. Both WT and radio-resistant strains develop zeocin-induced AR involving increased DSB rejoining. The radio- and zeocin-resistant strains AK-9-9 and H-3 again showed higher DSB rejoining capacity than the WT strain 137C. The higher resistance of strains H-3 and AK-9-9 did not abrogate their ability to adapt, albeit with a smaller magnitude as compared to the WT strain. The obtained results characterize new radio-resistant C. reinhardtii strains, which enrich the collection of resistant C. reinhardtii strains.
authors.affiliation: Central Laboratory of General Ecology-BAS, Sofia, Bulgaria.
authors.forename: E
authors.initials: E
authors.lastname: Dimova
authors.forename: M
authors.initials: M
authors.lastname: Dimitrova
authors.forename: D
authors.initials: D
authors.lastname: Miteva
authors.forename: Z
authors.initials: Z
authors.lastname: Mitrovska
authors.forename: N P
authors.initials: NP
authors.lastname: Yurina
authors.forename: P E
authors.initials: PE
authors.lastname: Bryant
authors.forename: S
authors.initials: S
authors.lastname: Chankova
mesh_terms: D000222:Adaptation, Physiological / Q000528:radiation effects*; D000818:Animals; D001761:Bleomycin / Q000633:toxicity*; D002470:Cell Survival / Q000528:radiation effects; D016825:Chlamydomonas reinhardtii / Q000166:cytology / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects*; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects; D004260:DNA Repair / Q000528:radiation effects; D007700:Kinetics; D011829:Radiation Dosage
chemical_list: D001761:Bleomycin; C105427:Zeocin